| PEOPLE | St. Marys | Monticello | United States |
| Population | 17,121 | 2,657 | 308,035,306 |
| Pop. Density | 761 | 827 | 87 |
| Pop. Change | 19.33% | 2.91% | 8.07% |
| Median Age | 31.6 | 36.9 | 37.3 |
| Households | 6,428 | 994 | 116,716,292 |
| Household Size | 2.64 | 2.6 | 2.58 |
| Male Population | 49.17% | 45.54% | 49.27% |
| Female Population | 50.83% | 54.46% | 50.96% |
| Married Population | 56.12% | 38.96% | 47.02% |
| Single Population | 43.88% | 61.04% | 52.98% |
| ESTIMATED TOTAL POPULATION BY AGE | | | |
| Age 0 to 4 | 8.24% | 8.09% | 6.56% |
| Age 5 to 9 | 7.65% | 7.79% | 6.61% |
| Age 10 to 14 | 7.48% | 6.36% | 6.71% |
| Age 15 to 17 | 4.60% | 4.89% | 4.21% |
| Age 18 to 20 | 2.90% | 2.37% | 2.95% |
| Age 21 to 24 | 8.80% | 6.25% | 7.01% |
| Age 25 to 34 | 14.79% | 12.08% | 13.33% |
| Age 35 to 44 | 12.66% | 11.89% | 13.33% |
| Age 45 to 49 | 12.94% | 12.83% | 14.61% |
| Age 50 to 54 | 12.94% | 12.83% | 14.61% |
| Age 55 to 59 | 9.99% | 12.76% | 11.84% |
| Age 60 to 64 | 9.99% | 12.76% | 11.84% |
| Age 65 to 74 | 6.67% | 7.38% | 7.05% |
| Age 75 to 84 | 2.45% | 4.52% | 4.24% |
| Age 85 and over | 0.84% | 2.79% | 1.78% |
| RACE | | | |
| White | 74.21% | 40.16% | 72.41% |
| Black | 18.68% | 56.45% | 12.61% |
| Asian | 1.37% | 0.30% | 4.75% |
| American Indian | 0.54% | 0.26% | 0.95% |
| Other | 5.21% | 2.82% | 9.28% |
| Hispanic | 0.00% | 5.09% | 16.35% |
| Non-Hispanic | 100.00% | 94.91% | 83.65% |
| FAMILY | | | |
| Married, w/children | 32.61% | 22.40% | 30.42% |
| Married, no children | 41.75% | 30.89% | 42.46% |
| Single, w/children | 16.62% | 24.74% | 14.39% |
| Single, no children | 9.01% | 21.96% | 12.73% |
| Divorced | 11.60% | 11.56% | 10.62% |
| Separated | 5.34% | 5.60% | 4.97% |
| Widowed | 4.09% | 10.64% | 6.14% |
| Now Married | 56.94% | 39.41% | 46.32% |
| Never Married | 22.04% | 32.79% | 31.95% |
